1. Technical Field
The present disclosure relates generally to medical/surgical ablation procedures. More particularly, the present disclosure relates to devices and microwave radiation delivery procedures utilizing microwave antenna assemblies and methods of controlling the delivery of microwave radiation to tissue.
2. Background of Related Art
In the treatment of diseases such as cancer, certain types of cancer cells have been found to denature at elevated temperatures (which are slightly lower than temperatures normally injurious to healthy cells). These types of treatments, known generally as hyperthermia therapy, typically utilize electromagnetic radiation to heat diseased cells to temperatures above 41° C. while maintaining adjacent healthy cells at lower temperatures where irreversible cell destruction will not occur. Other procedures utilizing electromagnetic radiation to heat tissue also include ablation and coagulation of the tissue. Such microwave ablation procedures, e.g., such as those performed for menorrhagia, are typically done to ablate and coagulate the targeted tissue to denature or kill it. Additionally, microwave therapy may be used in the treatment of tissue and organs such as the prostate, heart, and liver.
One advantage of microwave therapy is that microwave energy is able to non-invasively penetrate the skin to reach underlying tissue. Unlike low frequency RF therapy, which heats tissue with current, microwave therapy heats tissue within the electromagnetic field generated by a microwave antenna. The electromagnetic field generated by the microwave antenna generates a predictably large and/or uniform ablation region.
A second advantage of microwave therapy is that energy is rapidly delivered to the target tissue resulting in the reduction of surgical procedure time. During a typical surgical procedure microwave energy rapidly heats tissue to a target temperature and maintains the tissue above the target temperature for a required period of time.
Rapid delivery of heat to tissue may also result in the unwanted heating of healthy tissue or overheating of the target tissue. Unwanted heating of healthy tissue may be the result of creating an electromagnetic field larger than is required or excessive energy delivery. Overheating of tissue may result from excessive energy delivery or inconsistent heating of the target tissue.
Thus, the non-invasive use of microwave energy requires a great deal of control. This is partly why a more direct and precise method of delivering microwave radiation has been sought. The present disclosure provides a system for supplying microwave and various methods of delivering microwave radiation to tissue.